Malicious Office (OOXML) / .XLSX — malware analysis report

Static analysis result for SHA-256 8a96f3efb591cc18…

MALICIOUS

Office (OOXML) / .XLSX

111.6 KB Created: 2015-06-05 18:17:20 UTC Authoring application: Microsoft Excel 12.0000
MD5: bf32bc702f7e2df9cb4ee5d0cc4687ef SHA-1: 4222fc2616dfb6f2d193bc75e89f233e109a29f2 SHA-256: 8a96f3efb591cc18ec5c88ebaa18204fcfcdad1653d4da278449f88d8d20b579
260 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1059.001 PowerShell T1204.002 Malicious File

The file is an Excel document containing a Workbook_Open macro that executes a series of commands. The script attempts to create and execute a batch file at 'c:\programdata\jledshf.bat' and a VBScript at 'c:\programdata\sduoixo.vbs'. The VBScript appears to be a downloader, attempting to fetch payloads from multiple URLs, including 'http://reumatisclinic.com/-/scCn3mbiJRPsBkbR/C/'. The presence of the Workbook_Open macro and the execution of external scripts strongly indicate a malicious intent to download and execute further stages of malware.

Heuristics 6

  • ClamAV: Doc.Malware.Valyria-10004384-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Malware.Valyria-10004384-0
  • ClamAV detection on extracted artifact critical EXTRACTED_FILE_CLAMAV
    ClamAV flagged at least one file extracted from inside this sample. Even when the wrapping document carries no AV detection of its own, a hit on the carved artifact is a strong indicator the sample is a delivery vehicle.
  • Workbook_Open macro high OLE_VBA_WBOPEN
    Workbook_Open macro
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
  • Suspicious extracted artifact high EXTRACTED_FILE_STATIC_TRIAGE
    One or more files extracted from inside this sample matched static suspicious-content checks such as script obfuscation, encoded payload blobs, packed data, or execution/download terms.
  • VBA project inside OOXML medium OOXML_VBA
    Document contains vbaProject.bin — VBA macros present

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas
527d0656a0c2c323955d068683ef8f7e20c035cda247a1e24383595c0eb3403b
vba-macro oletools.olevba.extract_macros (decoded VBA source from OOXML) 7821 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved macro source contains an auto-exec entry point and execution/download terms.
vbaProject_00.bin
e2020f93cba119acebc9233897da0c5d1d4005cadfed5776708542df3a28bd1a
vba-project OOXML VBA project: xl/vbaProject.bin 37888 bytes
Detection
ClamAV: Doc.Malware.Valyria-10004384-0
Obfuscation or payload: likely
Carved macro source contains an auto-exec entry point and execution/download terms.